1. Field of the Invention
The invention relates to a server.
2. Description of the Related Art
A server mainly can be divided to three types according to its appearance, such as a pedestal server, a rack server and a blade server. The rack server occupies less space. The size of the rack server meets a standard. The width of the rack server is usually 19 inches, and the height is measured in unit (U) (1U equals to 1.75 inches). The 1U server is taken as an example. Although the 1U server is lighter, thinner and with full functions, it is difficult to expand components and update due to the height limitation according to the standard. As a result, the size of the rack server is enlarged (such as a 2U, 4U server) for accommodating more components.